The present invention relates to an inhalator suitable for administering a powder or powder composition, and a powder composition containing powders different in particle diameter from each other and a process for administering the powder composition using inhalators.
Generally, a powder inhalator is used for inhaling a powder or powder composition such as a powdered medicine into a human body through the oral or nasal cavity. The inhalator includes an inhalator body having an air intake path for introducing an ambient air and a suction opening through which an air-powder mixture within the inhalator body is sucked into the oral or nasal cavity. A powder receiving chamber for receiving the powder is disposed within the inhalator body and communicated with the outside of the inhalator body via the air intake path. An air-powder mixture path extends from the powder receiving chamber to the suction opening. The air-powder mixture is formed when the air is introduced into the powder receiving chamber through the air intake path. The air-powder mixture is then transmitted from the powder receiving chamber to the suction opening via the air-powder mixture path.
There are several types of powders different in aerodynamic mean particle diameter as follows: a powder having the aerodynamic mean particle diameter of not less than 7 xcexcm and depositing in an oral cavity or hypoglottis, a powder having the aerodynamic mean particle diameter of 5-7 xcexcm and depositing in a throat, a powder having the aerodynamic mean particle diameter of 3-5 xcexcm and depositing in a trachea, a powder having the aerodynamic mean particle diameter of 1-3 xcexcm and depositing in bronchi, and a powder having the aerodynamic mean particle diameter of not more than 1 xcexcm and depositing into alveoli, and the like. The powder having the aerodynamic mean particle diameter of not more than 3 xcexcm is required to surely reach affected areas of the human body. Also, the powder such as an acrid powder is preferably dosed in several parts upon being inhaled.
In addition, there has been proposed powder tobacco for use with the inhalator. The powder tobacco can be substituted for a usual smoking tobacco because the powder tobacco provides a smoking feeling upon being inhaled. When the powder tobacco is used, one dose of the powder tobacco is dispensed in parts from the inhalator upon each inhalation.
The human bronchi and alveoli exist in deeper portions of the human body. Therefore, in order to ensure stable deposit of the powder having the particle diameter of not more than 3 xcexcm in the bronchi and alveoli, it is preferable to dose the powder in parts, i.e., dispense a small amount of the powder each inhalation.
However, in the earlier technique, the whole amount of the powder received within the powder receiving chamber of the inhalator is dispensed from the inhalator by the inhalation substantially at one time. If a dose of the powder having the particle diameter of not more than 3 xcexcm is inhaled through the inhalator upon inhalation, a large amount of the powder dosed will be deposited in the oral cavity or trachea before being deposited in the bronchi and alveoli.
Further, there is known a process for administering a particulate medicament having a specific mean particle diameter into a patient""s lungs upon the patient breathing. International Publication No. WO97/36574 discloses a process and device for inhalation of particulate medicament. The process includes (i) providing an inhalator which contains at least one dose of medicament particles comprising spherical hollow particulates of respirable particle size suitable for deposition in a human lungs, and (ii) removing the spherical hollow particulates from the inhalator. In the earlier technique, the particulate medicament having the specific particle diameter is used with the inhalator, but there is not described inhalation on multi-purpose prescription, for instance, one-time inhalation of multiple particulate medicaments for the purpose of simultaneous deposition in different portions such as the trachea and the alveoli of the patient""s body. In order to follow the multi-purpose prescription, it is required that the patient repeatedly inhales separate doses of particulate medicaments for different prescriptions, takes a specific particulate medicament formulated for the multi-purpose prescription, or is treated with the combination of various prescriptions including peroral medicament, injection, application of fomentation, and the like.
It is an object of the present invention to provide an inhalator capable of dispensing one dose of a powder or powder composition in parts therefrom.
It is another object of the present invention to provide a powder composition containing powders different in particle diameter from each other and a process for administering the powder composition using inhalators, which are suitable for simultaneous deposition in different portions of the human body by one-time inhalation.
According to one aspect of the present invention, there is provided an inhalator for administering an air-powder mixture, comprising:
an inhalator body including an air intake path for introducing air into the inhalator body, and an air-powder mixture outlet for discharging the air-powder mixture from the inhalator body;
a powder receiving chamber adapted to receive a powder, the powder receiving chamber being disposed within the inhalator body and communicated with an outside of the inhalator body through the air intake path;
an air-powder mixture path adapted to transmit the air-powder mixture flowing from the powder receiving chamber to the air-powder mixture outlet;
an air-powder mixture reservoir adapted to temporarily store the air-powder mixture flowing from the powder receiving chamber, the air-powder mixture reservoir being disposed within the air-powder mixture path; and
a diluent air passage adapted to introduce a diluent air into the air-powder mixture reservoir, the diluent air passage communicating the air-powder mixture reservoir with the outside of the inhalator body.
According to a further aspect of the present invention, there is provided an inhalator for administering an air-powder mixture, comprising:
a casing including an air intake inlet for introducing air into the casing, and an air-powder mixture outlet for discharging the air-powder mixture from the casing;
powder receiving means for receiving a powder within the casing and permitting the powder to be admixed with the air introduced from the air intake inlet;
air-powder mixture storing means for temporarily storing the air-powder mixture passing through the powder receiving means;
diluent air passage means for permitting a diluent air to flow into the air-powder mixture storing means; and
air-powder mixture path means for permitting the air-powder mixture to flow from the powder receiving means to the air-powder mixture outlet via the air-powder mixture storing means.
According to another aspect of the present invention, there is provided a powder composition for use with an inhalator, comprising:
at least two kinds of fine particles selected from a first kind of fine particles having an aerodynamic mean particle diameter of not less than 7 xcexcm, a second kind of fine particles having an aerodynamic mean particle diameter of 5-7 xcexcm, a third kind of fine particles having an aerodynamic mean particle diameter of 3-5 xcexcm, a fourth kind of fine particles having an aerodynamic mean particle diameter of 1-3 xcexcm, and a fifth kind of fine particles having an aerodynamic mean particle diameter of not more than 1 xcexcm.
According to a further aspect of the present invention, there is provided a process for administering a powder composition using an inhalator, comprising:
preparing the powder composition containing at least two kinds of fine particles selected from a first kind of fine particles having an aerodynamic mean particle diameter of not less than 7 xcexcm, a second kind of fine particles having an aerodynamic mean particle diameter of 5-7 xcexcm, a third kind of fine particles having an aerodynamic mean particle diameter of 3-5 xcexcm, a fourth kind of fine particles having an aerodynamic mean particle diameter of 1-3 xcexcm, and a fifth kind of fine particles having an aerodynamic mean particle diameter of not more than 1 xcexcm;
supplying the powder composition to the inhalator; and
discharging the powder composition from the inhalator.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.